Monotypes are pulled impressions that were drawn or painted on a metal or plexiglass plate. The images are created through applications of ink that are rolled, brushed, daubed or otherwise applied and manipulated and then, with the material, usually paper, that is to accept an impression, are "pulled" with the use of a press.
Monotypes are inherently unique because only one or two impressions may be pulled before the ink is used up. Although there may be a second impression, it is quite different from the first in that most of the ink was lifted from the plate in its first pass through the press. The second impression, called a ghost or cognate, is much lighter or thinner and is more of a suggestion of the first. Each pulled impression may be considered a finished work or it may be further enhanced by the application of additional drawing or color.
. . . recent experimentations in the use of inks mixed with various viscosities of oil, applied in multiple layers on the same plate prior to printing have produced complex and exciting impressions. When technically well-executed, monotypes created in this manner are distinctly monotypes in their incredible fidelity to the artist's manipulations of ink, but have a remarkable transparent and "layered" quality that is not otherwise achievable.
— from Frank Howell, Monotypes
Collectors should be aware of the relative intrinsic worth of the contemporary works on paper loosely grouped as graphics: commercially produced posters which are photographically or mechanically printed are lowest in value; next in increasing value are the "original prints" such as silk screens/serigraphs, lithographs, etchings, collographs; next are the monoprints, each is part of a series but has unique elements; and of highest value, because each is unique, is the monotype. In terms of cost, the monotype fills the gap between lower-priced multiple prints and higher-priced original paintings on paper or canvas.